This thesis explores auditory feedback, designed around the ability of people to entrain their movements
with a rhythm. Phase denotes the progression through a movement and thus tracking phase
tracks progression through a movement. We show how to track phase using sensors and develop a
novel visual synchronization system that works with RGB-depth cameras. We use phase tracking
to produce auditory feedback that is synchronized with a user. Applications to walking, running,
cycling and speed skating demonstrate the methods and thirteen speed skating athletes test the
robustness and provide qualitative feedback of two of our synchronous auditory feedback systems.